Various techniques exist for displaying still and moving images. One common technique involves use of a conventional, visible-light projector with a passive display screen. The projector acts as a central transmission source from which visible light is projected onto the screen to display an image or images. This display method is often effective, though it may be disadvantageous in certain applications.
In many projection systems, all of the optical energy to display an image is generated by the projector. This often requires use of expensive bulbs or lamps within the projector that can consume a significant amount of power and generate substantial heat. Many systems employ cooling fans to dissipate the heat. The cooling fans often produce noise, in addition to adding to the manufacturing expense and complexity of the system. In addition, it is common for projection systems such as that described above to employ mirrors, color wheels, polarizers and other optical components between the light source and the display screen. These components can increase the expense of the system and make it difficult to maintain image quality when producing images of varying size and/or brightness. In many applications, there may also be a need to maintain a clear optical path between the projector and the display screen during image display.
The issues discussed above may be addressed to some extent through use of active display methods, in which the display screen includes emissive elements that independently output visible light to form images. However, these systems commonly employ complicated networks of wired addressing connections to deliver image data from a centralized content source to the plural emissive elements of the display screen. The large number of connections that are required increase the risk of connection failure, and can add to the expense of the system.